Has anyone actually used an Extrawheel trailer on a tandem?  I guess being shorter might help with parking and handling, while being a bit lighter is less important. But does being more upright than platform trailers mean they are less stable, at least during fitting and removal from the tandem? There's some mention of people thinking of trying them in other threads but if anyone has experience of using them on a long bike, and comparing with other trailers, I'd be very interested in hearing. Thanks.